Re: [HACKERS] Parallel Aggregation support for aggregate functionsthat use transitions not implemented for array_agg

On 6/6/17 13:52, Regina Obe wrote:
> It seems CREATE  AGGREGATE was expanded in 9.6 to support parallelization of
> aggregate functions using transitions, with the addition of serialfunc and
> deserialfunc to the aggregate definitions.
> 
> https://www.postgresql.org/docs/10/static/sql-createaggregate.html
> 
> I was looking at the PostgreSQL 10 source code for some example usages of
> this and was hoping that array_agg and string_agg would support the feature.

I'm not sure how you would parallelize these, since in most uses you
want to have a deterministic output order.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services